The invention relates to the technical field of mega-kilowatt class nuclear power station detection, and discloses a method for reducing fault rates of nuclear power units, a nuclear power unit ad a computer readable storage medium. The method comprises the following steps of: screening a key sensitive device; determining a category of the key sensitive device and a key sensitive part in the key sensitive device; and finally obtaining a maintenance scheme for the key sensitive part according to a failure mode analysis result of the key sensitive part and the category of the key sensitive device, to which the key sensitive part belongs. According to the method, devices in the nuclear power units are screened, and maintenance schemes are only customized for the devices causing stop and shutdown and parts thereof, so that the fault rates of the nuclear power units can be greatly reduced via consuming relatively few resources.